1. Field of Invention
The invention relates to a print control device and, in particular, to a print control device embedded in an engine simulation module and the test method thereof.
2. Related Art
The printer is one of the major peripheral devices of the computer. With increasing demands in the market, there is still a huge room for its development. As there are higher demands in the printing quality, the development in printing techniques is also important. This involves improvements in the resolution and printing speed.
A printer can be decomposed into a mechanical part and an electronic control part. The mechanical part refers to the print engine. The resolution of a printer is determined by the dot per inch (dpi) that the print engine can produce in each square inch. The higher the resolution is, the better quality the printer picture will have. The edges also become smoother. The printing speed of a printer usually refers to the top speed of the print engine. The electronic control part is the soul of a printer. It is the print control device built inside the printer, including the processor, memory, fonts, and video interface. The job of a print control device is to convert text and graph data transmitted from a computer host into bitmap data of 0 and 1, where 1 means a black dot while 0 means blank. Using the bitmap print data, the video interface controls the print engine to print ink at correct positions. Therefore, the print control device has to perform complicated text, image or graph processing. Thus, in addition to the resolution of the print engine, the actual resolution also relies on the adjustment of the print control device. Moreover, the top speed can be reached only when processing text data. It is very hard to print at the top speed for image or complicated print jobs. It is restricted by the print data transmission rate and the data processing rate of the print control device. Furthermore, to increase the printing quality, new techniques in enhancing the resolution and memory appear all the times. The logic circuit, peripheral, and memory interfaces integrated in the print control device are implemented using an application specific integrated circuit (ASIC). It can achieve the required printing quality through simple and minimal communications with the central processing unit (CPU) of the host computer.
Based upon the above-mentioned idea, to perform a printing system is a tremendous task. To shorten the test cycle for the ASIC in the print control device is particularly important. Since the print control device has to support various kinds of print engines, it is necessary to build an engine interface and a connector that are compatible with the print control device when designing a new print engine. This increases the test time and design costs. In order to shorten the test time, one can use a pattern generator to generate the required print engine signals. Using the pattern generator, different print engine signal can be generated in a programmable way. However, it is not easy to carry normal pattern generator. Another solution is a print engine simulator that uses a specially design circuit to provide the print engine signal. However, one still has to provide a new connector for a newly designed print engine in order to perform tests.